China · What to do now

You Already Sent the CAD Files. Seven Things to Do This Week.

The drawings went out over email or WeChat during quoting. Nothing was signed. Now the supplier has gone quiet, or something that looks like your product has appeared on Alibaba. Your position is weaker than it would have been with an agreement in place, and it is not empty — but the evidence degrades fast, and most of what you can still do costs nothing.

Responsible lawyer: Adrian Liu · PRC-licensed attorney, Xiamen · English & Chinese · Published September 29, 2026

Do these seven things before you contact the supplier

In that order. The most common mistake is sending an accusatory message first, which tells the other side exactly what to delete.

1. Export the correspondence in full

What to do: full email exports with headers, and a complete WeChat history export — not screenshots of selected messages.

Why it matters: screenshots are easy to challenge. Headers and unbroken message sequences carry timestamps and identify the sending account.

Escalate if: a chat history has already been cleared, or the person you dealt with has left the company.

2. Write the transfer chronology today

What to do: one document. What was sent, on what date, to which person, at which company, through which channel, and what the supplier said back.

Why it matters: this single page does more work than any individual piece of evidence, and you will not remember the sequence in six months.

Escalate if: you cannot establish which legal entity the recipient was acting for.

3. Keep the original files, not copies

What to do: preserve the files as they were sent, with metadata intact. Copy them to a separate location rather than re-saving them.

Why it matters: creation and modification dates help establish what existed when, which is the question a court asks.

Escalate if: the only copies you hold have been re-exported or edited since.

4. Collect the confidentiality signals you did use

What to do: look for markings on the files, restricted download links, access lists, instructions you gave about handling, anything limiting who saw what.

Why it matters: Chinese law protects information as a trade secret only where the holder took confidentiality measures, and measures are assessed as at the time before the misuse. An agreement is one recognised measure. It is not the only one.

Escalate if: you find nothing at all — that changes the strategy rather than ending it.

5. Capture the other side's material now

What to do: the listing, the catalogue page, the trade-show photograph, the sample. In China this is normally done through notarised preservation of the online content.

Why it matters: a notarial certificate carries evidentiary weight that a screenshot does not, and listings come down without warning.

Escalate if: the listing is already changing, or you have seen the product physically.

6. Say nothing accusatory yet

What to do: ordinary commercial contact is fine. An accusation is not.

Why it matters: the moment a supplier knows what you suspect, records start disappearing and the account you are dealing with goes quiet.

Escalate if: you have already sent one — say so early, because it changes what is realistically recoverable.

7. Get an agreement signed now, drafted to reach backwards

What to do: a new agreement can define the material already disclosed, acknowledge the earlier transfers, and bring them within the confidentiality and non-use obligations from here on.

Why it matters: it governs everything from signature forward, and the relationship is usually still live enough to get it signed.

Escalate if: the supplier refuses to sign anything covering what it already holds.

What the law actually gives you

Three provisions decide most of these matters, and none of them requires you to have signed anything first.

A duty exists even without a contract. A party who learns a trade secret while negotiating a contract may not disclose it or use it improperly, whether or not the contract is ever concluded, and is liable for loss caused (Civil Code art. 501). The difficulty is proving the loss, which is the job an agreement would have done in advance.

Your drawings can be the secret. A trade secret is information not known to the public, with commercial value, for which the holder took corresponding confidentiality measures (Anti-Unfair Competition Law, 2025 revision, art. 10). Signing a confidentiality agreement counts as a measure, so do marking, access restriction and controls on copying and storage (Fa Shi [2020] No. 7, art. 6), and the 2026 SAMR rules add permission tiering, data masking and operation logging for cross-border collaboration (Order No. 126, art. 9). The Supreme People's Court has also accepted that the information recorded in a complete set of drawings may constitute a trade secret (Fa Fa [2025] No. 1).

You do not have to prove the whole case. If you produce preliminary evidence that you took measures and that the secret was infringed, the other side must show it is not a trade secret. And if you also show it had a channel or opportunity to obtain the information and is using something substantially the same, it must prove it did not infringe (Anti-Unfair Competition Law, 2025 revision, art. 39).

That last provision is the one overseas buyers most often do not know about. It describes the position of a buyer who sent drawings to a factory and later found that factory selling an identical part.

If the supplier is already producing your design

Two procedural routes are worth knowing about before you spend anything.

Freezing assets. On an urgent pre-litigation application the court must rule within 48 hours and begin execution immediately; you provide security and must commence proceedings or arbitration within 30 days (Civil Procedure Law, 2023 revision, art. 104). Where the counterparty's assets are all in China, this is usually the most effective early step available to a foreign claimant.

Court-ordered evidence preservation. Where evidence may be lost or become hard to obtain, a party may apply for preservation, including before proceedings begin in urgent cases (art. 84). This matters when the proof sits inside premises you cannot enter.

There is also a criminal route. Using a trade secret in breach of a confidentiality obligation can be an offence, with loss of RMB 300,000 as one threshold for serious circumstances (Criminal Law art. 219; Fa Shi [2025] No. 5, art. 17). Suppliers understand that differently from a civil claim.

When you probably need a lawyer

You can do all seven steps above yourself, and you should, because they cannot be done retrospectively. Bring someone in when one of these is true:

You cannot work out which registered Chinese company received the files.
A product you believe is yours is already being sold, and you need the evidence fixed before it moves.
The supplier has refused to sign anything covering the earlier disclosure.
Tooling you paid for is sitting on the supplier's floor and the relationship is ending.
You are deciding whether to spend money on enforcement and want a straight read on whether it is worth it.

Three questions that come up every time

Is it too late to sign an NNN now?

No, and it is usually the right step. It governs everything from signature forward and can be drafted to cover material already disclosed. What it cannot do is create a confidentiality measure that existed at an earlier date, which is why steps 1 to 5 still matter.

The supplier says it developed the design independently.

That is the defence article 39 of the Anti-Unfair Competition Law is aimed at. Show that it had a channel or opportunity to obtain your information and that what it is using is substantially the same, and it has to prove independent development. That is provable, and the burden is on them.

Should I stop working with this supplier immediately?

Not reflexively. Ending the relationship abruptly cuts your access to information and to the tooling. Where moulds are involved, settle who owns them before you send a termination message.

Send the short version

Tell me what was sent, to whom, roughly when, and what has happened since. That is enough for me to say whether this is a drafting problem, an evidence problem or a dispute — and to scope the next step in writing before any paid work begins.

Describe your situation →Fees & process

Please do not send confidential drawings or technical files until we have confirmed how to transfer them. An enquiry does not create a lawyer–client relationship.

Have a China-side question?

Briefly tell us what happened, who the Chinese counterparty is, and what outcome you need. A lawyer will review the outline before suggesting the next step.